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Biomedical subjects

C Hannig

Publications and source records attributed to C Hannig.

At least 19 recordsLinked to original sources

[MSCT for staging and response evaluation of esophageal cancer].

Squamous cell carcinomas and adenocarcinomas account for the majority of cases of esophageal cancer. Esophageal cancer often is diagnosed in advanced stages as clinical symptoms are lacking in early stages. The major aims of imaging in esophageal cancer are to determine local tumor extension (T and N staging), to rule out systemic disease (M staging), and to assess response to neoadjuvant therapy (response evaluation). CT is still inferior to endoscopic ultrasound in differentiating T stages and detecting regional lymph node metastases. However, it plays a central role in determining infiltration into adjacent organs (T4 stage) and in ruling out distant metastases. Multislice-CT (MSCT) offers the possibility of reconstructions, which often help to assess the relationship between tumor and anatomic landmarks like the tracheobronchial tree or the diaphragm. First results of CT volumetry for response evaluation are promising; however, PET and PET/CT with the glucose analogue FDG are the standard methods to evaluate response to neoadjuvant therapy.

Esophageal Neoplasms↗

Argon plasma ablation of gastric inlet patches in the cervical esophagus may alleviate globus sensation: a pilot trial.

BACKGROUND AND STUDY AIMS: Globus sensation and/or sore throat have been associated with both gastroesophageal reflux disease and the presence of a gastric inlet patch. There have been no reports, however, on whether ablation of heterotopic mucosa in the cervical esophagus leads to improvement of chronic globus sensation. PATIENTS AND METHODS: Ten patients with a histologically proved gastric inlet patch who complained of chronic globus sensation and/or sore throat were included in this prospective pilot study. After a thorough assessment, including videofluoroscopy, laryngoscopy, manometry, and 24-hour two-channel pH monitoring, patients underwent argon plasma coagulation (APC) to ablate the heterotopic mucosa. A questionnaire with a visual analog scale ranging from 0 to 10 was used for assessment of globus sensation, sore throat, and other typical or atypical reflux symptoms. Follow-up examinations (including symptom assessment) were performed 4 weeks and 8 weeks after APC therapy. RESULTS: Ablation of the gastric inlet patch resulted in a significant reduction of median symptom scores for globus sensation (from 2.7 to 0) and sore throat (from 2.8 to 0) 8 weeks after therapy ( P < 0.05), but there was no improvement in other reflux-related symptoms. Acid reflux in the distal and proximal esophagus, determined by two-channel pH monitoring, did not change after therapy. CONCLUSIONS: Our preliminary data suggest that ablation of gastric inlet patches by APC can alleviate chronic globus sensation or sore throat. Acid reflux or its treatment is unlikely to influence these results. A randomized and blinded study is warranted.

Adult↗

Recovery of peroxides in saliva during home bleaching--influence of smoking.

UNLABELLED: The study aimed at determining hydrogen peroxide recovery in saliva during use of different home bleaching products by smokers and non-smokers. Peroxide recovery was evaluated with respect to the safe level reported in the literature. Determination of peroxide levels in saliva was performed with peroxidase, phenol and 4-aminoantipyrin in a photometric method. Four different bleaching regimens were used by 10 smokers and 10 non-smokers: Whitestrips, Vivastyle (tray-based) and two paint-on products (Crest Night Effects, Colgate Simply White). Whole saliva was collected and total amount of peroxide (mg) released during the 60 min bleaching period was determined: Colgate Simply White: 2.67 +/-0.88 (non-smokers); 2.66 +/- 1.17 (smokers); Crest Night Effects: 0.23 +/- 0.13 (non-smokers); 0.25 +/-0.16 (smokers); Vivastyle: 2.47 +/- 0.82 (non-smokers), 2.44 +/- 1.31 (smokers); Whitestrips: 1.39 +/- 0.62 (non-smokers), 2.02 +/- 1.86 (smokers). In terms of amount of peroxide kg(-1) body weight the bleaching systems led to a single exposure of 0.004-0.046 mg kg(-1), which is distinctly less than safe daily dose of 0.26 mg kg(-1) day(-1), if calculated for a small person (58 kg). The criterion smoker versus non-smokers had no influence on peroxide levels in the oral cavity. CONCLUSION: Smoking did not appear to impact the anti-oxidant defence capacity of the oral cavity with respect to degrading peroxides released from bleaching products. Significantly lower amounts of peroxides were detected in saliva during application of the paint-on product Crest Nights Effects compared with the other bleaching systems.

Carbonates↗

Recolonization of mutans steptococci on teeth with orthodontic appliances after antimicrobial therapy.

The aim of the present study was to compare the recolonization pattern of mutans streptococci on densely colonized teeth with and without fixed orthodontic appliances after treatment with a 40 per cent chlorhexidine (CHX) varnish (EC 40, Explore). Healthy subjects free of carious lesions requiring fixed orthodontic appliance treatment but with high bacterial mutans streptococci saliva counts were recruited (n = 10). For baseline registration, plaque from buccal sites was sampled and cultivated on Dentocult strips. Following professional tooth cleaning, CHX varnish was applied to all teeth for 8 minutes. Subsequently, orthodontic brackets and bands were inserted in either the upper or lower arch. Eight weeks after varnish application the degree of recolonization with mutans streptococci was reassessed on the buccal sites. Statistical analysis showed that recolonization with mutans streptococci was significantly higher (P < 0.05) on teeth with orthodontic appliances. The results indicate that the use of fixed orthodontic appliances creates artificial environments suitable for the proliferation of mutans streptococci after CHX varnish suppression.

Analysis of Variance↗

Suitability of a malachite green procedure to detect minimal amounts of phosphate dissolved in acidic solutions.

The study describes the suitability of a colorimetric method (malachite green procedure) for detection of minimal amounts of phosphate (7.3-29.1 micromol/L) in different acidic solutions (hydrochloric acid, oxalic acid, maleic acid, perchloric acid, tartaric acid, citric acid, lactic acid and acetic acid) adjusted to pH 2.0. A mixture of the respective phosphate concentrations with distilled water served as control. The experiments were run with ten repeats in series. Assessment of intra- and interassay coefficient of variation and lower limit of quantification revealed that depending on the acid used, the applied method is a reliable and suitable tool to detect and quantify minimal phosphate contents in small samples of acidic solutions that have the potential to cause erosive dental lesions.

Acids↗

Enamel fluoride uptake of a novel water-based fluoride varnish.

Aim of the in situ-study was to evaluate fluoride retention in sound and demineralised enamel after application of a novel water-based fluoride (0.12% F) varnish Mirafluorid (Hager and Werken, Germany) compared to the resin-based varnish (2.26% F) Duraphat (Colgate, USA). Each five enamel specimens were prepared from 60 bovine incisors. In 150 of these specimens, incipient lesions were produced with acidic hydroxyethylcellulose (pH 4.8; 72 h), 150 specimens were not demineralised. The samples were equally (n=100) allotted to three groups (A: Mirafluord, B: Duraphat, and C: control). Each 80 specimens (40 demineralised and 40 sound) were varnished with either Mirafluorid or Duraphat or remained unfluoridated (controls). The other specimens were used for measuring base-line fluoride content of the respective tooth. Each six specimens (three demineralised and three sound) were fixed in intraoral appliances worn for 5 days by 10 volunteers in three series (A-C). During the experiment, the samples were brushed twice daily with fluoridated toothpaste. KOH-soluble and structurally bound fluoride (0-30 and 31-60 microm depth) was determined immediately, 1, 3 and 5 days after fluoridation. Fluoride uptake was calculated as compared to base-line content and statistically analysed. Immediately after fluoridation, uptake of KOH-soluble and structurally bound fluoride was similar for Mirafluorid and Duraphat in both demineralised and sound enamel. However, at day 1, 3 and 5 statistically significantly higher amounts of KOH-soluble and structurally bound fluoride were found in the samples treated with Duraphat. For Mirafluorid only the uptake for KOH-soluble fluoride and structurally bound fluoride in the first enamel layer (0-30 microm) of the demineralised samples was significantly higher compared to the controls (C). It is concluded that the novel fluoride varnish Mirafluorid deposits less KOH-soluble and structurally bound fluoride on both demineralised and sound enamel compared to Duraphat under in situ-conditions.

Adult↗

[Non-destructive, preclinical evaluation of root canal anatomy of human teeth with flat-panel detector volume CT (FD-VCT)].

PURPOSE: Successful endodontic diagnostics and therapy call for adequate depiction of the root canal anatomy with multimodal diagnostic imaging. The aim of the present study is to evaluate visualization of the endodont with flat-panel detector volume CT (FD-VCT). MATERIALS AND METHODS: 13 human teeth were examined with the prototype of a FD-VCT. After data acquisition and generation of volume data sets in volume rendering technology (VRT), the findings obtained were compared to conventional X-rays and cross-section preparations of the teeth. RESULTS: The anatomical structures of the endodont such as root canals, side canals and communications between different root canals as well as denticles could be detected precisely with FD-VCT. The length of curved root canals was also determined accurately. The spatial resolution of the system is around 140 microm. Only around 73 % of the main root canals detected with FD-VCT and 87 % of the roots could be visualized with conventional dental X-rays. None of the side canals, shown with FD-VCT, was detectable on conventional X-rays. In all cases the enamel and dentin of the teeth could be well delineated. No differences in image quality could be discerned between stored and freshly extracted teeth, or between primary and adult teeth. CONCLUSION: FD-VCT is an innovative diagnostic modality in preclinical and experimental use for non-destructive three-dimensional analysis of teeth. Thanks to the high isotropic spatial resolution compared with conventional X-rays, even the minutest structures, such as side canals, can be detected and evaluated. Potential applications in endodontics include diagnostics and evaluation of all steps of root canal treatment, ranging from trepanation through determination of the length of the root canal to obturation.

Adult↗

Three-dimensional, non-destructive visualization of vertical root fractures using flat panel volume detector computer tomography: an ex vivo in vitro case report.

AIM: To detect and to visualize radiographically vertical root fractures in extracted teeth with a prototype of a novel, high resolution, three-dimensional flat panel volume detector computer tomograph (FD-VCT) system. SUMMARY: Five teeth with root fillings and clinical symptoms such as fistulas and isolated periodontal pockets of 8 mm or more were extracted after dental radiography indicating lateral or periapical lesions. Vertical root fractures or cracks were suspected because of the symptoms and clinical findings were evident after extraction in all cases but fracture lines were not visible on routine dental radiographs acquired before extraction. The extracted teeth were explored with a prototype of a FD-VCT. Using the FD-VCT, in all cases vertical root fractures or crack lines could be detected clearly in different views, depiction-modes and cross-sections at a spatial resolution of 140 microm. The evaluation of the fracture lines and teeth could be performed in three-dimensional views. The FD-VCT findings were confirmed by detailed inspection of the extracted teeth. KEY LEARNING POINTS: The FD-VCT is an innovative diagnostic tool for non-destructive, three-dimensional evaluation of extracted teeth in pre-clinical and experimental studies. The FD-VCT allows precise visualization and evaluation of vertical root fractures or cracks in extracted teeth. Clinical application of the system may be possible if technical modifications reduce the exposure dose: the high resolution detector systems of the FD-VCT should be combined with radiation systems that focus the radiation to the area of interest.

Humans↗

Influence of tea on intrinsic colour of previously bleached enamel.

Aim of the study was to evaluate the influence of tea applied at various time intervals after bleaching of enamel on intrinsic tooth colour. Ninety bovine specimens were distributed among six groups (A-F, n=15). The samples of group A-D were bleached with the 10% carbamide peroxide (CP) gel VivaStyle for 8 h, followed by storing in artificial saliva for the remaining period of the day. The specimens were removed from the saliva at different intervals (A: 0 min, B: 60 min, C: 240 min) and immersed in freshly prepared black tea for 10 min. Group D (bleaching, no tea), E (no bleaching, but tea) and F (no bleaching, no tea) served as controls. These procedures were repeated for 8 days. Colour was measured at baseline, after each day, and after final cleaning using the CIELab-system. Then Deltab (initial b-value - final reading), DeltaL, and composite colour (DeltaE) were statistically analysed. External bleaching (A-D) led to a distinct whitening effect with lower Deltab- (=reduction in yellow) and higher DeltaL-values (=increase in brightness) compared with controls. The Deltab- and DeltaL-values of the samples A-C were not significantly different from the samples which were bleached only. No significant difference was observed comparing specimens of group A-C. It is concluded that application of tea directly after bleaching with 10% CP does not significantly effect the outcome of a bleaching treatment irrespective of the time interval elapsed between the bleaching procedure and the contact of the tooth surface with tea.

Animals↗

[Deglutition disorders in neurological patients. A prospective study of diagnosis, pattern of impairment, therapy and outcome].

We performed a prospective study on 208 patients with neurogenic dysphagia who were consecutively admitted for swallowing therapy over a 3-year period. The most frequent etiology was stroke (48%). Videofluoroscopic and/or fiber optic endoscopic evaluation of swallowing were performed in 204 patients. Swallowing therapy was comprised of restitution methods, compensation, and adaptation, each of which was applied in more than 80% of the patients. Mean duration of swallowing therapy was 2 months (full oral patients 1 month, patients dependent on tube feeding or tracheostomy 2.5 and 3.5 months, respectively). Fifty-five percent of the patients initially dependent on tube feeding were full oral feeders after swallowing therapy. A target variable reflecting functional feeding status showed significant improvement after swallowing therapy, also in patients with a disease duration of more than half a year, ruling out spontaneous recovery as a sole explanation of amelioration. The following variables were the main contributors to outcome prediction: functional feeding status, Barthel index, duration of disease, and degree of aspiration as shown by endoscopy.

Adolescent↗

Observation of the swallowing process by application of videofluoroscopy and real-time magnetic resonance imaging-consequences for retronasal aroma stimulation.

The process of eating and drinking was observed in vivo by application of videofluoroscopy, a dynamic X-ray technique, as well as real-time magnetic resonance imaging. The study was aimed at elucidating the timing and performance of the physiological organs involved in mastication and swallowing, mainly the tongue, the pharynx and the soft palate (velum palatinum). It was shown for the first time that effective physiological barriers do exist during food consumption that are capable of retaining volatiles such as helium within the oral cavity. These barriers allow the access of odorants to the nasal cavity only at certain times during the eating process. Their effectiveness is related to the texture of the food as well as the amount of food material present in the oral cavity and, thereby, directly influences retronasal aroma perception.

Adult↗

Assessment of gunshot bullet injuries with the use of magnetic resonance imaging.

BACKGROUND: Magnetic resonance imaging (MRI) is rarely used for preoperative assessment of shotgun injuries because of concerns of displacing the possibly ferromagnetic foreign body within the surrounding tissue. METHODS: A total of 56 different projectiles underwent MRI testing for ferromagnetism and imaging quality in vitro and in pig carcasses with a commercially available 1.5-MRI scan. Image quality was compared with that of computed tomographic scans. RESULTS: Projectiles with ferromagnetic properties can be distinguished easily from nonferromagnetic ones by pretesting the motion of an identical projectile within the MRI coil. When ferromagnetic projectiles were excluded, MRI yielded the more precise images compared with other imaging techniques. Projectile localization and associated soft tissue injuries were visualized without artifacts in all cases. CONCLUSIONS: When ferromagnetic foreign bodies are excluded by pretesting their properties within the MRI with a comparative projectile, MRI portends an excellent imaging procedure for assessing the extent of injury and planning the removal by surgery.

Animals↗

Intramural esophageal hematoma after cardioversion.

Intramural esophageal hematoma is a very rare condition. We report a case of a 40-year-old male, presenting with retrosternal pain and dysphagia. On the day before admission tarry stool and minimal vomiting of old blood was noticed. Diagnostic procedures showed an intramural esophageal hematoma, which had developed 2 weeks and 3 days after cardioversion and anticoagulation therapy. Etiology, differential diagnosis, the diagnostic approach and a brief review of the literature are discussed.

Adult↗

[Videocinematography and pre- and postoperative diagnosis of lip-maxillary-palatal clefts].

Videocinematography is a valuable tool in the diagnostic workup and planning of functional surgery in cleft patients. The high resolution and depiction of the finest mucosal structures in motion allow objective and dynamic assessment of the individual velopharyngeal function. A total of 170 cleft patients were examined by videocinematography, and the results were compared to nasoendoscopy and to the clinical examination. The marked superiority of this radiological technique with regard to clearness of depiction and ease of use is shown. It can therefore be recommended without reservation for the pre- and postoperative assessment of cleft patients.

Adolescent↗